Aqueous emulsions of epoxy resins have long been known and used, e.g. in formulating adhesives, coatings, etc. In particular they have found use in formulating sizing compositions for glass fibers which are to be imbedded in a resinous matrix as mechanical reinforcement for articles fabricated therefrom, especially where such resinous matrix is itself an epoxy resin and the article is a tank or pipe fabricated by winding essentially continuous strands of the sized glass fibers about a suitable mandrel while concurrently impregnating with the matrix resin.
It is a particular object of the present invention to provide an aqueous co-emulsion of epoxy resin and mineral oil adapted for formulating improved sizing compositions for glass fibers.